On Rhamphocephalus prestwichi, Seeley, an ornithosaurian from the Stonesfield slate of Kineton / by H.G. Seeley.
- Harry Govier Seeley
- Date:
- 1880
Licence: Public Domain Mark
Credit: On Rhamphocephalus prestwichi, Seeley, an ornithosaurian from the Stonesfield slate of Kineton / by H.G. Seeley. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![[.From the Quarterly Journal of the Geological Society for February 1880.] On Rhamthocephalus Prestwichi, Seeley, an Ornitiiosaurian from the Stonesfield Slate of Kineton. By H. G. Seeley, Esq., F.R.S.jE.G.S., Professor of Geography in King’s College, London. Prof. Prestwick has obtained from tho Stonesfield slate of Kineton, near Stow-on-the-Wold, a small slab which makes a valuable con- tribution to our knowledge of the structure of the skull in Ornitho- saurs from the British Lower Secondary rocks. This specimen is little more than a cast from the upper surface of the cranium, not unlike in general character to the form originally described by Goldfuss as Omitliocephalus Munsteri. The skull itself was un- fortunately in the corresponding slab, which has not been preserved ; but a few slight fragments of bone remain sufficient to show the dense osseous tissue which is usual in Pterodactyles. Tho specimen yields a clear impression, which displays the proportions of the cranial bones, and the sutures between them, in a way so distinct as to enable me to state that this animal was certainly different generically from every other type which has hitherto been described. Whether, however, it pertained to a distinct species from those in- dicated by the fossils from Stonesfield which have already been figured by Professors Huxley and Owen is a matter upon which some doubt may be felt; but bearing in mind the relatively large size of the jaws and teeth in those fossils, I am strongly of opinion that this specimen indicates a smaller kind of animal, in which the dentary apparatus was less developed, and I therefore venture to suggest for it a specific name. The remarkable feature which leads mo to consider this specimen to be the type of a new genus is its singular analogy to the Croco- dilian skull, which has never been displayed to the same degree in any other Ornithosaur. The fragment shows the parietal, frontal, prefrontal, and nasal bones ; all these are arranged on the Crocodilian plan, and yet the proportions of the parietal and frontal regions are in no respect those of a Crocodile. All the bones are smooth on the upper surface. The parietal region is long, flattened above, slightly convex in length, with a moderate median depression posteriorly, where there are some longitudinal striations, as though the end of a supraoccipital here overlapped the parietal bone; but the bone terminates transversely in a sharp clean posterior edge, which is sinuous, being convex in the middle and concave towards the sides, where the bone widens out, giving off lateral wings towards the squamosal region. The median suture of the parietal bones can be traced, though it is not quite in the middle line. The bones be- come constricted from side to side, the constriction being greatest behind the middle, where they appear to be naturally notched on each side. I do not see the signification of these notches, unless they indicate the anterior termination of squamosal bones which](https://iiif.wellcomecollection.org/image/b22412451_0005.jp2/full/800%2C/0/default.jpg)
